1. Field of the Invention
The present invention relates to an image processing device and a controlling method thereof, and particularly to the image processing device and the controlling method thereof which result from improving an inter-line process of a read image signal from plural line sensors arranged parallel to each other in a colored-image processing device such as a copying machine or a scanner.
2. Description of the Related Art
Conventionally, concerning a colored-image processing device such as a copying machine or a scanner, it has been considered necessary that respective reading drives of the plural line sensors are controlled at different timings when the image on a manuscript is read by using the plural line sensors for RGB arranged parallel to each other.
As a technique that meets these requirements, there has been known, for example, a method disclosed in Japanese Patent No. 2632871 (refer to Jpn. Pat. Appln. KOKAI Publication No. 1-109966; it will be indicated as Document 1 below).
That is, in the method disclosed in Document 1, it is designed so that the reading timings of the respective line sensors will be controlled by implementing an interpolation process on image signals (RGB signals) arranged parallel to each other and output from three line sensors that read different lines on a manuscript in accordance with reading magnifications of the manuscript.
In this case, the method disclosed in Document 1 is designed so that outputs from the respective line sensors will be made to synchronize in all channels. Therefore, a line memory for three RGB line signals becomes necessary.
That is, if the outputs from the respective line sensors are made to synchronize in all channels in this manner, when, for example, reference of plural lines is necessary for formation of a distinction signal, a filter process and the like at the latter step, the line memory for three RGB line signals becomes necessary even when only one line signal is needed since extraction is implemented among signals of the plural lines synchronized with the line signal.
However, in this case, there is a problem that the capacity of the line memory for the line signals that are not used for the reference is wasted since only one line signal is needed.
An object of the present invention is to solve the above-mentioned problems that conventional techniques have, and to provide an image processing device and a controlling method thereof whose image reproducibility can be improved by implementing a necessary reference process by using at least one line signal as an ahead-reading signal when reading an image on a manuscript by using plural RGB line sensors arranged parallel to each other so that the capacity of a used memory can be mitigated while a substantially wider area can be referred to.
In order to accomplish the above-mentioned objects, according to a first aspect of the present invention, there is provided an image processing device comprising:
plural line sensors arranged parallel to each other in a predetermined order and with a predetermined interval, which read different lines on a manuscript, respectively;
a delay module which outputs an image signal output from at least one of the plural line sensors with a delay for a number of lines according to a number of pixels which corresponds to shifts of reading positions of the plural line sensors; and
an ahead-reading signal acquiring module which acquires the image signal output from at least one line sensor other than a last stage line sensor of the plural line sensors as an ahead-reading signal,
wherein the image processing device outputs the image signal wherein the shifts of the reading positions of the plural line sensors are corrected by the delay module, and outputs the ahead-reading signal acquired by the ahead-reading signal acquiring module.
Moreover, according to a second aspect of the present invention, there is provided the image processing device according to the first aspect, wherein the plural line sensors are arranged so that they can acquire desired signals as the ahead-reading signal output by the ahead-reading signal acquiring module.
Moreover, according to a third aspect of the present invention, there is provided the image processing device according to the first aspect further comprising a line interpolation module which implements line interpolation to the image signal output from at least one of the plural line sensors in correspondence with a change of the shifts of the reading position of the plural line sensors according to a reading magnification value of the manuscript.
Moreover, according to a fourth aspect of the present invention, there is provided the image processing device according to the first aspect, wherein the delay module includes a first delay module which outputs an image signal output from at least one line sensor other than the last stage line sensor of the plural line sensors with a delay for a number of lines according to the number of pixels which corresponds to the shifts of reading positions of the plural line sensors; and
the ahead-reading signal acquiring module acquires the ahead-reading signal from the first delay module while including an ahead-reading signal plural-line reference module which enables to refer to plural lines of the acquired ahead-reading signal.
In order to accomplish the above-mentioned objects, according to a fifth aspect of the present invention, there is provided an image processing device comprising:
plural line sensors arranged parallel to each other in a predetermined order and with a predetermined interval, which read different lines on a manuscript, respectively;
delay means for outputting an image signal output from at least one of the plural line sensors with a delay for a number of lines according to a number of pixels which corresponds to shifts of reading positions of the plural line sensors;
ahead-reading signal acquiring means for acquiring the image signal output from at least one line sensor other than a last stage line sensor of the plural line sensors as an ahead-reading signal; and
reading position shift correcting means for correcting the shifts of reading positions of the plural line sensors based on the image signal delayed by the delay means and the ahead-reading signal acquired by the ahead-reading signal acquiring means.
Moreover, according to a sixth aspect of the present invention, there is provided the image processing device according to the fifth aspect, wherein the plural line sensors are arranged so that they can acquire desired signals as the ahead-reading signal output by the ahead-reading signal acquiring means.
Moreover, according to a seventh aspect of the present invention, there is provided the image processing device according to the fifth aspect further comprising line interpolation means for implementing line interpolation to the image signal output from at least one of the plural line sensors in correspondence with a change of the shifts of the reading position of the plural line sensors according to a reading magnification value of the manuscript.
Moreover, according to an eighth aspect of the present invention, there is provided the image processing device according to the fifth aspect, wherein the delay means includes first delay means which outputs an image signal output from at least one line sensor other than the last stage line sensor of the plural line sensors with a delay for a number of lines according to the number of pixels which corresponds to the shifts of reading positions of the plural line sensors; and
the ahead-reading signal acquiring means acquires the ahead-reading signal from the first delay means while including ahead-reading signal plural-line reference means for enabling reference to plural lines of the acquired ahead-reading signal.
In order to accomplish the above-mentioned objects, according to a ninth aspect of the present invention, there is provided a controlling method of an image processing device comprising plural line sensors arranged parallel to each other in a predetermined order and with a predetermined interval, which read different lines on a manuscript, respectively, comprising:
outputting an image signal output from at least one of the plural line sensors with a delay for a number of lines according to a number of pixels which corresponds to shifts of reading positions of the plural line sensors;
acquiring the image signal output from at least one line sensor other than a last stage line sensor of the plural line sensors as an ahead-reading signal; and
outputting the image signal wherein the shifts of the reading positions of the plural line sensors are corrected and the ahead-reading signal.
Moreover, according to a tenth aspect of the present invention, there is provided the controlling method of the image processing device according to the ninth aspect, wherein the plural line sensors are arranged so that they can acquire desired signals as the ahead-reading signal.
Moreover, according to an eleventh aspect of the present invention, there is provided the controlling method of the image processing device according to the ninth aspect further comprising:
implementing line interpolation to the image signal output from at least one of the plural line sensors in correspondence with a change of the shifts of the reading position of the plural line sensors according to a reading magnification value of the manuscript.
Moreover, according to a twelfth aspect of the present invention, there is provided the controlling method of the image processing device according to the ninth aspect, wherein the delay is performed by a first delay element which outputs an image signal output from at least one line sensor other than the last stage line sensor of the plural line sensors with a delay for a number of lines according to the number of pixels which corresponds to the shifts of reading positions of the plural line sensors; and
the ahead-reading signal acquisition is performed by acquiring the ahead-reading signal from the first delay element while including an ahead-reading signal plural-line reference element which enables reference to plural lines of the acquired ahead-reading signal.
The above first, fifth, and ninth aspects correspond to a first embodiment which will be described below.
In these aspects, by implementing a necessary reference process by using the image signal output from at least one line sensor other than the last stage line sensor of the plural line sensors as an ahead-reading signal, the capacity of a used line memory can be mitigated while a substantially wider area can be referred to. As a result, referring to the wider area can be implemented with a lower cost so that image reproducibility is improved.
The above second, sixth, and tenth aspects correspond to the first embodiment which will be described below.
In these aspects, in addition to the first, fifth, and ninth aspects above, by arranging the plural line sensors so that the reading position of the signal that is desired to be ahead-read will be at the head, referring to the wider area can be implemented with lower cost concerning the desired signal as a result. Therefore, the image reproducibility is further improved.
The above third, seventh, and eleventh aspects correspond to a second embodiment which will be described below.
In these aspects, in addition to the first, fifth, and ninth aspects above, the area with the same width can always be referred to with lower cost regardless of the magnification during changing magnification of a scanner so that the reproducibility of the area image improves.
The above fourth, eighth, and twelfth aspects correspond to third and fourth embodiments which will be described below.
In these aspects, in addition to the first, fifth, and ninth aspects above, it becomes possible to refer to the wider area with less memory by commonly using the delay memory for adjusting position as the memory for referring to the area. Therefore, referring to a further wider area can be implemented with lower cost so that the image reproducibility improves.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.